title: Creating favorable geometries for directing organic photoreactions in alkanethiolate monolayers.
abstract: The products of photoreactions of conjugated organic molecules may be allowed by selection rules but not observed in solution reactions because of unfavorable reaction geometries. We have used defect sites in self-assembled alkanethiolate monolayers on gold surfaces to direct geometrically unfavorable photochemical reactions between individual organic molecules. High conductivity and stochastic switching of anthracene-terminated phenylethynylthiolates within alkanethiolate monolayers, as well as in situ photochemical transformations, have been observed and distinguished with the scanning tunneling microscope (STM). Ultraviolet light absorbed during imaging increases the apparent heights of excited molecules in STM images, a direct manifestation of probing electronically excited states.
authors.affiliation: California NanoSystems Institute and Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA.
authors.forename: Moonhee
authors.initials: M
authors.lastname: Kim
authors.forename: J Nathan
authors.initials: JN
authors.lastname: Hohman
authors.forename: Yang
authors.initials: Y
authors.lastname: Cao
authors.forename: Kendall N
authors.initials: KN
authors.lastname: Houk
authors.forename: Hong
authors.initials: H
authors.lastname: Ma
authors.forename: Alex K-Y
authors.initials: AK
authors.lastname: Jen
authors.forename: Paul S
authors.initials: PS
authors.lastname: Weiss